The purpose of this program project grant is to investigate the biology of marrow transplantation and improved allogeneic, syngeneic, and autologous transplantation in clinical malignancy, diseases of marrow failure and certain genetic diseases. The proposal is made up of six projects: 1) Clinical Trials: This project is designed to investigate ways to improve the result of marrow purging and improve methods of patients supportive care. 2) Graft-versus-Host Reaction and Disease: The aims of this project are to investigate the basic mechanisms involved and the therapeutic prevention and treatment of Graft-versus-Host Disease. 3) Pharmacology in Bone Marrow Transplantation: The aims of this project are to provide knowledge as to the pharmacokinetics and mechanism of agents employed in pre-operative regimens, resistance to these agents and development of new anti tumor agents and agents used to prevent and treat graft-versus-host disease. 4) Biology of Viral Infection in Bone Marrow Transplantation: The aims of this project are to define the role BK virus as a pathogen in transplant patients, the role of EBV virus in the pathogenesis of Hodgkin's Disease and the effect of adoptive transfer of anti-EBV cellular immunity in EBV positive Hodgkin's Disease. 5) Experimental Hematology in Bone Marrow Transplantation: The aims are to study the function of BCR-ACL in CML as to cell proliferation, survival and differentiation, develop new clinical strategies for treatment of CML based on preclinical studies and apply principles learned from CML to the study of both normal and malignant hematopoiesis. 6) Core components: This project represents the core of the program and includes administrative and support services, RLFP analysis, statistics, graft engineering, pathology, and outpatient services.